Tejas versus JF-17 Thunder: the Indian fighter is well ahead of the Chinese-Pak one - Broadsword by Ajai Shukla - Strategy. Economics. Defence.

Home Top Ad


Thursday 6 May 2021

Tejas versus JF-17 Thunder: the Indian fighter is well ahead of the Chinese-Pak one

India and Pakistan’s approach to light fighters is a study in contrast with lessons for indigenisation


By Ajai Shukla

Business Standard, 7th May 21


Since its first flight in 2001, India’s homegrown Tejas light combat aircraft (LCA) has faced two decades of unrelenting opposition from the Indian Air Force (IAF). For long, the fighter pilots who make all the key decisions in the IAF opposed the indigenous fighter’s entry into service, arguing that it lacked the performance needed for surviving in the highly-contested airspace that would prevail in an Indo-Pakistan or Sino-Indian war. Only last year was the Ministry of Defence (MoD) able to push through an order for 83 Tejas Mark 1A fighters – an improved version of the aircraft that will start being delivered in a couple of years. With this endorsement from the IAF, there is interest in the fighter from other regional air forces, including those of Malaysia and Sri Lanka.


In sharp contrast to the IAF, the Pakistan Air Force (PAF) wholeheartedly supported its own fighter – the JF-17 Thunder, which Pakistan and China co-designed as a no-nonsense, light fighter that met unambitious performance benchmarks without endless scrutiny and comparisons with the cutting edge in military aviation. Consequently, the JF-17 is already inducted in numbers into the PAF and is encountering interest from other countries (though, notably, not from China) who are encouraged by the PAF’s enthusiastic endorsement.


With the National Democratic Alliance government setting great store by “Make in India” and “Atmanirbharta” (self reliance), it is worth comparing the Indian and Pakistani approaches to their light fighters and drawing lessons for indigenisation.


In defining the Tejas programme as it did, the Defence R&D Organisation (DRDO) set itself the aim of leapfrogging technologies and catching up with the world. This high-risk gambit involved going straight for a fourth generation (Gen-4), state-of-the-art aircraft. Old-timers admit it was pure technological arrogance to reason: “I’ve never made an aircraft earlier, but I’ll start by developing a Gen-4 fighter”. Astonishingly, this risky strategy worked!


In contrast, China-Pakistan chose a very different, low-risk path: To utilize the technologies China already had and realise an aircraft into service quickly and cheaply. The JF-17 is a heavily re-engineered MiG-21, which allowed a more modest development trajectory. The core of a fighter development problem is technology and risk management. Since China already had the technologies, the risk was minimal. The PAF knowingly chose a less capable fighter, whose performance shortfalls could be compensated for with numbers.


In taking forward the Tejas project, the Aeronautical Development Agency (ADA) – the DRDO agency that was made responsible for developing the Tejas – ambitiously incorporated four Gen-4 technologies into the new fighter. These were (a) Unstable design and digital flight control; (b) Building major aircraft structures (wings, fuselage, etc) with lightweight composite materials; (c) Microprocessor based controls for on-board utilities (such as fuel); and (d) An all-glass cockpit, which meant the pilots flew and fought with smart, digital control panels, enabling them to do more.


The Tejas fighter’s most advanced Gen-4 technology lay in its fully unstable design, which improves flight performance. With an unstable design, safety demands that flight control systems must be quadruplex – which means catering for three levels of failure. Ninety per cent of the design effort goes into managing failure. The Tejas was, therefore, the most advanced aircraft in the IAF’s fleet. Even the Mirage 2000, with a similar delta-wing design, is a Gen-3 aircraft with “relaxed stability”, but not a fully unstable design. That is half a generation behind the Tejas.


Tejas’ other big Gen-4 advantage comes from the use of lightweight composite materials. Over 45 per cent of the Tejas’s total weight comes from composite materials, including its fuselage, vertical tailfin, skin, spars, elevons, rudder, the air brakes and the landing gear doors. Having thus saved a significant amount of weight, the Tejas can carry more payload, increasing its operational range and strike power. In contrast, the JF-17, a Gen-3 aircraft that China developed for export, is constructed of aluminium alloy. As a result, it is almost a tonne heavier than the Tejas and, therefore, carries less fuel and armaments.


However, the Tejas has a problem with its air intakes design. This stems from initial confusion about its role, which was to replace the MiG-21 as the IAF’s light fighter. Since the MiG-21 was designed for high-speed interceptions at speeds of Mach 2 (twice the speed of sound, or 2,500 km per hour), the Tejas designers worked for a top speed of Mach 1.8. However, they chose fixed air intakes, which are suitable only for speeds up to Mach 1.4. Higher speeds require more sophisticated air intakes, incorporating moving intakes, cones, etc. The Tejas’ fixed air intakes reduce its thrust by 30-40 per cent. Even so, the fighter is good for Mach 1.2-1.4, the regime where most air battle engagements actually occur. 


Lower speeds save fuel and increase mission flexibility. Experience showed that when the MiG-21 climbed at Mach 2 to high altitude and the engagement was aborted, it was left without the fuel needed for another mission and had to return to base for refuelling. For that reason, the Tejas Mark 2 will be optimised for air combat engagements at Mach 1.2. With the design skills in ADA, that can easily be done.


Both the Tejas and JF-17 have had problems in choosing engines. The Tejas was to be powered by the DRDO’s Kaveri turbofan engine but, due to development delays, ADA chose the General Electric F-404 instead. In China, the JF-17 developers chose the Russian RD-93 after-burning turbofan due to its low fuel consumption and price. However, the RD-93 delivers inadequate power – a dry thrust of 50 kiloNewtons (kN) and 81.3 kN thrust with afterburner. This is significantly lower than that of the Tejas Mark 2. Its GE F-414 engine, with 35 per cent more thrust than the F-404, will deliver a robust 60 kN of dry thrust and 98 kN with afterburner. The JF-17 is likely to be upgraded to the Chinese WS-13 engine, but its development is clouded in uncertainty. 


Upgrading to a higher performance engine requires the freedom to redesign the basic aircraft. A higher thrust engine such as the F-414 or the WS-13 is heavier than the engine it replaces and, therefore, upsets the aircraft’s balance, forces design changes and, being heavier, consumes more fuel. So an upgraded engine often delivers disappointing performance.


In sum, the Tejas has emerged as a light multirole fighter with Gen-4 technology and innovation, such as its unique aerodynamic configuration, the use of composite materials and its advanced avionics. With its design in Indian hands, it can be easily modified into variants, such as a naval fighter or a lead-in fighter trainer. . It can also be tailored to suit export customers’ requirements.


The JF-17, in contrast, is a Gen-3­­ fighter that cannot be tailored for export customers beyond a point. On the plus side, its off-the-shelf materials, sub-systems and systems cut costs and reduce design risks, making it a cheap and reliable fighter for air-to-air combat. As a Chinese analyst summed up: “The JF-17 is the aircraft of today and the Tejas is the aircraft of tomorrow.”


  1. While you certainly mention Tejas versions, it's unclear which version of the JF-17 your article is comparing performance of. The Block 2 is considered as a gen 4 fighter, and the latest Block 3 is definitely considered a Gen 4+ fighter by commonly held global standards. While the engines are an issue for both as you point out, you also fail to mention the threat of US sanctions on export of the Tejas engines and even future sale of them to India after an S400 purchase by India.

    A professional analysis would require a truly unbiased and version by version comparison.

    Why don't you compare the current Block 3 "B" or the eminent "A" with the current Mack 1A?

    By the time a Mack 2 is any kind of commercial production and is actually inducted in the IAF (if it does) it will be several years in the future, so the M2 comparison right now is essentially a theoretical exercise on your part.

    Disappointing analysis.

    1. Yes, one would expect from a person like Ajai to be truelly honest, not like youtubers who are after clicks only. Its your second article of comparision between JF17 and Tejas. I commented last time too which were delted later on. That which version of JF17 you are comparing with which version of Tejas ? (2) If India aimed to produced a Gen-4 and in which they succeeded then how long it took them too ? If it was 30 years ago and they had aimed to get a 4th Gen Jet and they produced one ( if its a 4th Gen ) then it cant be considered a "success" because other countries are going after Gen-6. Again Ajai, you should be writting for the internaional audience not just Indians otherwise there are many youtubers who are better in mixing reality with false news to earn a few $. Hope next time you would comeup with honest analysis.

    2. keep dreaming. US is not a fool to sanction India unlike turkey. Turkey was a NATO member, India is not.
      At best even if sanctioned, it will not be more than a air slap on the hand.

    3. After reading A.shukla’s article above, I felt extremely disappointed of him being reduced to modi goadi media level.

  2. Teja is far superior than raffle too. Hope this satisfy your ego problems. 1😁🤣

  3. That was a pro Indian article. No independent person can agree to it. Things will clear up when Tejas will compete in test excerises outside Indian soil.

  4. The first Tejas Mk1A will fly in 2022 with serial production starting in 2023 if all goes according to the plan. JF Thunder Block 3 flew in 2019 production has already started and first deliveries of teh first batchcare expected at this year's end or early 2022

  5. jf17 is a nice fit fighter for paki core millitary philosophy of surviving from one war to another. They do not need to win battles, they just need to survive after the battle ends. So that they can use that excuse and take a higher % of paki budget for buying arms. That will allow their generals to make commissions in $'s to purchase more pizza chain franchises.

    India on the other hand has to win wars

  6. Other than calling the scientists arrogant(which is in bad taste, it's their so called arrogance that has now squarely put us ahead on contemporary technology), you are spot on. JF17 is more like Indian version of assembled Jaguars. Tejas is our own baby.

  7. India must focus on oxygen supply for Indians. Pakistan is not a soft target. BJP goons usually target innocent and vulnerable people.
    So I think this comparison is a propaganda.

    India must focus on saving lives

  8. one of the most plus advantage with JF-17 is all indigenous weapons (mixing with chinese and Pakistan) package having with HOBS WVR, BVR, anti-radar missile, JOW, ER-Kit bomb etc... And all are well combat proven.

  9. Tejas.....
    Plz fight with COVID....... Arrange oxygen for Indian people..... Tejas r superior or not.... It come after the oxygen supply to urs people....look for the health of Indian people....

  10. Doesn't seem like something you would write. The tone is more suited for the pseudo patriots for thumping their chest. Are you comparing jf-17 block 1 with LCA mk2?

  11. The worrying part here is that after 20+ years someone has to explain to us why LCA is better.

  12. An excellent, unbiased analysis. Some Pakistani commentators are complaining that the JF-17 Block 3 hasn't been compared, and so this analysis is flawed.

    What new stuff does the Block 3 have ? 3-axis FBW ? Its been on the Tejas since 20 years.

    Does Block 3 have more composites ? Still doesn't beat Tejas Mk.1 which has the highest percentage of composites by area among all contemporary fighters (its built with composites from ground up, instead of having them slapped on like JF-17).

    Will Block 3 have more weapon stations ? Unlikely. An AESA radar ? A Chinese one, that they themselves don't use. The Uttam radar will be featured in Tejas Mk.1A which is under production.

    Any other new feature that Block 3 has, like radar jammers or missile approach warning receivers ? Tejas Mk.1 has them already.

    JF-17 Block 3 can simply be compared to the baseline Tejas Mk.1. Its just a catch-up version. The previous Blocks are clearly inferior to the Tejas Mk.1.

  13. This article is poorly written and the research needing to be done is kinda incomplete. Why would Tejas Mark 2 be used in a comparison here when it's yet to be built? On paper every airplane "sounds" good. Truth is that just comparing to platforms is an exercise in futility as so many factors are involved, e.g. exploiting data network, BVR missiles, maximising the aircraft's potential consistently. I feel that the JF17 being operational for so many more years than the Tejas is a massive advantage to Pakistan. During this time, the PAF has not just used the platform tactically but also in exercises with PLAF (against Flanker versions). Pakistan exploited the gap in the BVR missile range during the Balakot operations, and this is a critical factor. Missile coming at you doesnt know or care if it came from a Gen 3 or Gen 4 aircraft.

    And quite frankly, who cares about exporting when no more than 8-10 Tejas aircrafts are built each year? Also the Tejas does not have a long enough range yet, this aspect has been omitted in this article. And it doesn't really matter if the PLAF doesn't use the JF 17, they have 600+ Flanker versions, 500 + J 10s!

    On the plus side, I celebrate the many indigenous advancements in glass cockpit, composite materials etc. It behoves well for a country like India to invest in these technologies even though they are table stakes in aircraft design and production.


Recent Posts

Page 1 of 10412345...104Next >>Last